Mining and large scale excavating operations require fleets of haul vehicles to transport excavated material such as ore or overburden from an area of excavation over roads to a predetermined destination. For such an operation to be profitable the fleet of haul vehicles must be efficiently operated. Efficient operation of these vehicles is affected by the quality of the roads over which they travel. For example, the grade and character of the roads in combination with the size of vehicle payload have direct effects on cycle time, vehicle health, and fuel usage which, in turn, directly affect productivity and profitability of the mining and excavating operations. During the past 30 years, haul vehicles have developed from haul trucks capable of moving 20 tons of material to haul trucks that transport more than 350 tons. Increasing payload sizes exert large stresses on the roads over which the haul vehicles operate. Large stresses on the roads increase the propensity of damage to the roads and the haul trucks that operate on them.
Traditionally, maintenance of the roads at a mining or excavating site has been highly reactive. That is, the road defects are repaired as they occur, with little planning or scheduling of repair events. This ad-hoc road maintenance approach is inefficient and increases costs by over or under maintenance of the roads. For example, in some instances damage on a stretch of the road is allowed to accrue until reaching a point when travel along the road becomes dangerous. Repair at this stage is expensive, both in terms of lost productivity and inability to schedule the machines and labor required for the repair at an opportune time. In other instances, a preventive maintenance schedule is slavishly followed without regard to the effect of the damage on the operation of the mine. In this case, too much money and effort may be spent on unnecessary road maintenance. As the trend of increasing payload size continues, a holistic approach to manage the maintenance of haul roads is desired to keep operational costs down.
One approach at improving road conditions is disclosed in U.S. Pat. No. 5,817,936 issued to Schricker (the '936 patent) on Oct. 6, 1998. In particular, the '936 patent discloses detecting an abnormal road surface condition by sensing machine parameters as a mobile machine traverses a segment of the road. These parameters are then used to calculate a resistance factor for the road segment. The calculated resistance factor is compared with an average resistance factor and an abnormal condition of the road surface can thus be detected. If an abnormal condition is detected, the road is repaired to correct the condition.
Although the method of the '936 patent may sufficiently detect an abnormal surface condition of the road, it does not perform a holistic economic analysis using all available information of road condition and its impact on vehicles that operate on them to provide an optimized road maintenance approach. Rather, the method disclosed in the '936 patent is limited to detection of road damage only, followed by routine reactive repair when resources become available.
The present disclosure is directed to overcoming one or more of the problems set forth above.